Below is a simple but highly accurate scientific calorie calculator, along with five evidence-based tips on how to sustainably reduce your calorie intake.
Enter your details in the calculator below to figure out how many calories you should be eating per day to either maintain or lose weight.
The average woman needs to eat about 2,000 calories per day to maintain her weight, and 1,500 calories per day to lose one pound of weight per week. Meanwhile, the average man needs 2,500 calories to maintain, and 2,000 to lose one pound of weight per week.
However, this depends on numerous factors. These include age, height, current weight, activity levels, metabolic health, and several others.
A calorie is a unit that measures energy. Calories are usually used to measure the energy content of foods and beverages. To lose weight, you need to eat fewer calories than your body burns each day.
Calories are simply a measure of energy.
It’s a known fact that to gain weight, more calories need to be entering your body than leaving it.
Conversely, you lose weight if more calories leave your body than enter it.
That said, cutting calories without taking the foods you eat into account is usually not a sustainable way to lose weight.
Though it works for some people, most end up hungry and eventually give up on their diet.
For this reason, it’s highly recommended to make a few other permanent changes to help you maintain a calorie deficit in the long term, without feeling starved.
Here are 5 evidence-based diet and lifestyle changes that have been shown to help people lose weight.
1. Eat more protein
When it comes to losing weight, protein is the king of nutrients.
Adding protein to your diet is the simplest, most effective, and most delicious way to lose weight with minimal effort.
Studies show that protein both increases your metabolic rate and helps curb your appetite (
Protein is also by far the most filling nutrient. One study showed that people who ate 30% of calories from protein automatically ate 441 fewer calories per day (
In other words, you can easily increase calories out and reduce calories in just by adding protein to your diet.
Protein can also help fight cravings, which are a dieter's worst enemy.
In one study, consuming 25% of daily calories from protein reduced obsessive thoughts about food by 60% and cut the desire for late-night snacking by 50% (
If you want to lose weight sustainably and with minimal effort, consider making a permanent increase in your protein intake.
Summary Increasing your protein intake can boost metabolism, fight cravings, and significantly reduce appetite. This can lead to automatic weight loss.
2. Avoid sugary soft drinks and fruit juices
Another relatively easy change you can make is to eliminate liquid sugar calories from your diet.
This includes sodas, fruit juices, chocolate milk, and other beverages with added sugar.
These products are among the most fattening aspects of the modern diet, as your brain doesn’t register liquid calories in the same way as it registers solid calories.
Studies have shown that sugary drinks are strongly linked to an increased risk of obesity, with one study in children showing a 60% increased risk for each daily serving of a sugar-sweetened beverage (13).
There is no physiological need for these beverages, and the long-term benefits of avoiding them can be enormous.
Summary It’s important to avoid sugary soft drinks and fruit juices, as liquid sugar is the single most fattening aspect of the Western diet.
3. Drink more water
One very simple trick to increase weight loss is to drink more water.
Drinking about 8 glasses (equal to 68 ounces or 2 liters) of water per day can make you burn about 96 more calories.
In one 12-week study, drinking 17 ounces (0.5 liters) of water half an hour before meals made people lose 44% more weight (
When combined with a healthy diet, drinking more water (especially before meals) appears to be helpful if you need to lose weight.
Summary Studies have shown that drinking water can boost metabolism. Drinking it half an hour before meals can help you eat fewer calories.
4. Exercise and lift weights
When you eat fewer calories, your body compensates by saving energy, making you burn less.
This is why long-term calorie restriction can significantly reduce metabolism.
Plus, it can lead to loss of muscle mass. Muscle is metabolically active, so this can reduce metabolism even further.
The only proven strategy to prevent this effect is to exert your muscles by lifting weights.
Of course, if you’re trying to lose weight, you don't want to just lose fat, you also want to make sure that you take care of your muscles.
If you can't get to a gym, consider doing bodyweight exercises, such as push-ups, squats, and sit-ups, at home.
Doing some cardio, including walking, swimming, or jogging, can also be important — not necessarily for weight loss but for optimal health and general well-being.
Summary Lifting weights is important, as it reduces muscle loss and prevents your metabolic rate from slowing.
5. Reduce your carb intake
Not only that, but low carb diets also have many other benefits for health, especially for people with type 2 diabetes or metabolic syndrome.
But you don’t have to go low-carb. Simply ensure that you eat quality, fiber-rich carb sources, focusing on whole, single-ingredient foods.
If you stick to whole foods, the exact composition of your diet becomes less important.
Summary Cutting carbs may aid weight loss by reducing appetite and making you eat fewer calories.
Many websites and apps can help you track your calorie intake.
It’s highly recommended to use a calorie counter for at least a few days to see how many calories, carbs, protein, fat, fiber, vitamins, and minerals you’re truly eating.
Seeing the numbers like this can often be an eye-opener.
How many calories you need per day depends on whether you want to maintain, lose, or gain weight, as well as various other factors, such as your gender, age, height, current weight, activity levels, and metabolic health.
Reducing calories does not have to mean starving yourself. A few simple diet and lifestyle changes, including exercising, properly hydrating, and increasing protein and reducing carb intake, can help you lose weight and feel satisfied.